Amaranth Unveils 85-micron Bioresorbable Stent

June 19, 2018 – Amaranth Medical offered new details about its 85-micron Defiance bioresorbable scaffold (BRS) recently at EuroPCR 2018. The new bioresorbable stent is comparably in size to market-leading DES without the risks associated with a permanent implant.

The company said when the clinical study of Defiance begins in 2019, the device will have the thinnest struts of any bioresorbable scaffold ever tested in clinical development. For comparison with the market-leading stents, the Xience V has 81-micron struts, and Resolute and Endeavor are 91-microns.

“The prospect of a viable BRS with 85-micron struts — as thin as a [metallic] drug-eluting stents (DES) — is unthinkable with the limitations of most polymer production techniques," said Antonio Colombo, M.D., director of the hemodynamics division at Ospedale San Raffaele in Milan, Italy and co- principal investigator of the Amaranth RENASCENT BRS studies. "If Defiance produces clinical results comparable to Amaranth’s other pipeline products, it could be a truly unique offering.”

Amaranth CEO Kamal Ramzipoor, said there have been many failures in the development of BRS due to the limitations of first-generation polymer technology, resulting in larger strut sizes, making the devices harder to use and with poorer outcomes than today's metallic DES. “However, the benefits of a bioresorbable scaffold remain compelling and we believe will drive interest in our product line, especially in our thin-walled Aptitude and two sub-100-micron scaffolds, Magnitude and Defiance. These BRS possess the desired characteristics to meet industry expectations of strength, flexibility and ease of use," Ramzipoor said.

At EuroPCR, Amaranth also provided updates on the company’s sirolimus-eluting BRS products during a satellite symposium. Amaranth’s Magnitude, the world’s first 98-micron BRS to generate patient follow-up results in a clinical study, showed success. Implantation success was high at 97.3% for the 70 patients in RENASCENT III international, multi-center study. An interim analysis of 48 patients nine months following their procedure revealed a low rate of major adverse cardiac events (6.3% MACE due to two cases of peri-procedural cardiac enzyme elevation) and a binary restenosis rate of 7.9%. To date, there have been no reported incidence of scaffold thrombosis. Strut apposition and coverage was present in the great majority (97%) of struts analyzed by optical coherence tomography (OCT) in the patients implanted with Magnitude. Detailed nine-month imaging and safety data was presented at the symposium by Alaide Chieffo, M.D., the research director of the interventional cardiology unit at Ospedale San Raffaele in Milan, Italy.

“These RENASCENT III results are early in the patient follow-up window," Chieffo explained. "Additional, larger clinical studies would be needed to confirm these findings. Even so, they are promising and speak to the capabilities of the Amaranth polymer technology to develop scaffolds that are thin and strong enough to rival metal stents.”

“At 98 microns, the Magnitude scaffold has started to match the technical and mechanical performance of metallic drug-eluting metal stents,” added Juan F. Granada, M.D., president and CEO of the Cardiovascular Research Foundation (CRF) and co-principal investigator of the Amaranth studies. “The thin struts on Magnitude allow the easier navigation of the scaffold through more tortuous anatomies; its mechanical strength allows operators to use a more “conventional” deployment strategy.”

Amaranth’s EuroPCR symposium also included a presentation and discussion of the efficacy and safety findings from the 60-patient, multi-center, international RENASCENT II study of Aptitude, a BRS with a strut thickness of 115 microns. As previously reported, at nine months following implant, RENASCENT II patients showed a high clinical device success rate (98.3%) and no cases of restenosis or scaffold thrombosis. At nine months, OCT analysis showed nearly complete strut coverage (97%) and a low MACE rate of 3.4% (two non-Q wave myocardial infarctions related to non-target lesions). Chieffo presented new interim two-year follow-up results during the EuroPCR symposium, which show no additional MACE events and no incidence of scaffold thrombosis.

A key slide from Elnabawi's presentation, showing cardiac CT plaque evaluations, showing the impact of psoriasis medication on coronary plaques at baseline and one year of treatment. It shows a reversal of vulnerable plaque development.